On what should have been the happiest day of his life, Prince William was plagued by memories of the saddest: the day his mother, Princess Diana, was killed in a car crash in August 1997.
In Katie Couric's ABC special, The Jubilee Queen, the Duke of Cambridge, 29, admits it was "very difficult" getting married without his mother looking on.
"I sort of prepared myself beforehand so that I was mentally prepared," William says of his April 29, 2011 wedding day. "I didn't want any wobbly lips or anything going on. It's the one time since she's died where I've thought to myself, 'It would be fantastic if she was here,' and just how sad really for her, more than anything, not being able to see it."
William continued: "I think she would have loved the day, and I think, hopefully, she'd be very proud. I'm just very sad that she's never going to get a chance to meet Kate [Middleton]."
His younger brother, Prince Harry, 27, also wished his mother could have seen her firstborn tie the knot with Middleton, 30.
"I think she had the best seat in the house, probably," Harry says. "But yeah, she would have loved to have been there."
The Jubilee Queen With Katie Couric airs Tuesday at 9 p.m. EST on ABC.
This article originally appeared on Usmagazine.com: Prince William: I'm "Very Sad" Princess Diana Never Got to Meet Kate Middleton